Clamping cartridge for panel-type products

ABSTRACT

A clamping cartridge for releasably clamping a plurality of panel-type articles in generally parallel spaced-apart manner comprising: a frame; clamping means spaced-apart along the frame, said clamping means being generally oriented perpendicular to their direction of spacing and being normally biased towards a closed position; actuation means operable in association with said clamping means for opening and closing said clamping means in unison; and a slide associated with each of said clamping means.

FIELD OF THE INVENTION

The invention relates to a clamping apparatus for holding and positioning a plurality of items and, more particularly, a clamping cartridge for releasably clamping a plurality of generally planar objects.

BACKGROUND OF THE INVENTION

There are numerous instances where a series of sheet or panel-type products need be transported and/or stored. When all such items are identical, there is usually no need to be concerned over loading and unloading sequences. However, when the items are not identical, any sequenced access must be predetermined which usually entails predetermined loading strategies and, furthermore, random access may simply not be possible. Moreover, where the items vary in thickness, group clamping typically requires individual (i.e. time-consuming) adjustment of respective clamping mechanisms.

Existing solutions are either cumbersome, inefficient and/or unable to address all of the user-defined requirements. These requirements and the challenges were, mainly, the following: 1) the ability to load a variety of panel sizes and thicknesses within a given packaging unit, for example in a custom metal rack; 2) the ability to access, remove or replace any one or all panels individually, without affecting the rest of the panels; 3) the ability to grip and hold the parts (panels) during transport and storage; 4) user-friendly operating sequences; 5) reliability and ease of maintenance; and 6) cost effectiveness.

U.S. Pat. No. 2,946,453 describes a supporting rack for automobile windshields having a plurality of pairs of posts, half of which are fixed while the other half are associated with a movable frame so as to enable the movable posts to be moved in unison against the fixed posts to provide a clamping action therebetween. U.S. Pat. No. 2,953,253 illustrates a windshield carrier having a pair of fixed parallel slotted frames for receiving windshields therein. Clamping is effected either by an associated pair of movable parallel frames having corresponding slots therein (FIG. 1) or a series of pressure elements movable through a linkage (FIG. 8). The devices of both of these patents have unitary movement of all clamping elements, but the fixed spacing structure will only function to clamp the thickest of a plurality of planar articles of variable thicknesses.

U.S. Pat. No. 4,093,251 discloses a windshield carrier having a plurality of posts in two rows. A rotatable friction element is disposed atop each post which can be rotated into engagement with the surface of a windshield disposed between adjacent posts. The friction elements are individually rotatable. This device has the capacity to accommodate a plurality of planar articles of variable thicknesses, but each clamping mechanism must be operated independently.

U.S. Pat. No. 4,202,452 shows a supporting rack for breakable articles comprising a plurality of spaced apart posts in parallel rows. An inflatable tube is provided on the exterior of each post and, thus, between adjacent posts. The tube is inflatable to contact the articles disposed between the posts in a secure and safe fashion. This apparatus has the capacity to accommodate a plurality of planar articles of variable thicknesses and is operable to close and release all clamps in unison. However, the apparatus requires the hydraulic/pneumatic system to be operating/pressurized at all times when clamping is required. Thus, if the system fails, the clamping function ceases.

U.S. Pat. No. 4,785,936 illustrates a device for holding flat objects, such as circuit boards, wherein a plurality of slots are provided in a tray having cooperating blocks with ridges moveable relative thereto. In order to accommodate a variety of thicknesses of boards, resilient cushions are disposed between the ridges which compress to the extent necessary. The device is spring biased in the open position. This device has the capacity to accommodate a plurality of planar articles of variable thicknesses and is operable to close and release all clamps in unison. Like with U.S. Pat. No. 4,202,452, this apparatus is open in its relaxed state.

Applicant's United States Patent Application Publication US 2004/0245195 discloses one known solution to the short comings in the prior art and is incorporated herein by reference. A clamping cartridge which comprises a plurality of clamping mechanisms spaced apart on a frame or chassis. The clamping mechanisms are generally oriented perpendicular to their direction of spacing. The clamping mechanisms are of the type that comprise a pair of relatively movable jaws which are biased together. An actuator operable in association with the clamping mechanisms serves to open and close the jaws of the clamping mechanisms in unison. While the clamps are closeable in unison, they are individually self-adjusting so the extent of closure for each clamp is dependent on the thickness or presence of an inserted article. The clamping cartridges are useful in a variety of applications requiring clamping of one or more articles in a side-by-side relationship. One such application is a transportation/storage rack which includes a plurality of aligned horizontal and vertical clamping cartridges for clamping the edges of glass panels. This prior art clamping cartridge is described in detail below and is hereinafter referred to as “Applicant's Prior Art Cartridge”.

In the Applicant's Prior Art Cartridge, debris can become lodged in and around the cam wheels and cause jamming.

SUMMARY OF THE INVENTION

The present invention relates to a clamping cartridge for releasably clamping a plurality of panel-type articles in generally parallel spaced-apart manner comprising: a frame; clamping means spaced-apart along the frame, said clamping means being generally oriented perpendicular to their direction of spacing and being normally biased towards a closed position; actuation means operable in association with said clamping means for opening and closing said clamping means in unison; and a slide associated with each of said clamping means.

In another embodiment, the invention relates to a clamp for a clamping cartridge comprising a base and two arms forming a jaw with the ends of said arms biased toward each other and boots on said ends.

In another embodiment, the invention relates to a retainer for a clamping cartridge comprising: a base; a tooth extending from one side of the retainer, said tooth including a top inclined surface, a back wall and two side walls, and a flange.

In another embodiment, the invention relates to a clamping cartridge for releasably clamping a plurality of panel-type articles in generally parallel spaced-apart manner comprising: a plurality of spaced-apart clamps, said clamps being generally oriented perpendicular to their direction of spacing and each having a pair of relatively movable jaws; actuation means operable in association with said clamps for causing the jaws of all said clamps to move in unison relative to one another, said actuation means comprising a cam operable between the jaws of each clamp whereby movement of the cam causes the relative movement of said jaws; said jaws being normally biased so as to be individually self-adjusting to the presence of an edge of one or more panel-type articles placed therebetween; slide means associated with said clamps.

Other systems, methods, features and advantages of the invention will be, or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the following claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like reference numerals designate corresponding parts throughout the different views.

FIG. 1A is a perspective view of the preferred embodiment of the Applicant's Prior Art Cartridge in its closed/clamping position.

FIG. 1B is an elevational view of the clamping cartridge of FIG. 1A.

FIG. 1C is a plan view of the clamping cartridge of FIG. 1A.

FIG. 1D is an end view of the clamping cartridge of FIG. 1A.

FIG. 2A is a perspective view of the preferred embodiment of the Applicant's Prior Art Cartridge in its open/released position.

FIG. 2B is an elevational view of the clamping cartridge of FIG. 2A.

FIG. 2C is a plan view of the clamping cartridge of FIG. 2A.

FIG. 2D is an end view of the clamping cartridge of FIG. 2A.

FIG. 3A is a plan view of the spring body of one of the clamping mechanisms shown in the clamping cartridge of FIG. 1A.

FIG. 3B is a bottom view of the spring body of FIG. 3A.

FIG. 3C is an elevational view of the spring body of FIG. 3A.

FIG. 3D is an enlarged end elevational view of the spring body of FIG. 3A.

FIG. 4A is a side elevational view of one of the clamp arms of one of the clamping mechanisms shown in the clamping cartridge of FIG. 1A.

FIG. 4B is an end elevational view of the clamp arm of FIG. 4A.

FIG. 4C is a plan view of the clamp arm of FIG. 4A.

FIG. 5A is a plan view of the support frame of the clamping cartridge of FIG. 1A.

FIG. 5B is a side elevational view of the support frame of FIG. 5A.

FIG. 5C is an end elevational view of the support frame of FIG. 5A.

FIG. 6A is a perspective view of one of the cam wheels of the clamping cartridge of FIG. 1A.

FIG. 6B is an elevational view of the cam wheel of FIG. 6A.

FIG. 6C is a plan view of the cam wheel of FIG. 6A.

FIG. 6D is a side elevational view of the cam wheel of FIG. 6A.

FIG. 7A is a plan view of the cam shaft of the clamping cartridge of FIG. 1A.

FIG. 7B is an elevational view of the cam shaft of FIG. 7A.

FIG. 7C is an end view of the cam shaft of FIG. 7A.

FIG. 7D is an elevational view of an alternate cam shaft having a different mechanism for its rotation.

FIG. 7E is an end view of the alternate cam shaft of FIG. 7D.

FIG. 8A is a perspective view of the clamping cartridge according to the preferred embodiment of the invention in which a number of panel-type articles have been retained.

FIG. 8B is an elevational view of the clamping cartridge of FIG. 8A.

FIG. 8C is a plan view of the clamping cartridge of FIG. 8A.

FIG. 8D is an end view of the clamping cartridge of FIG. 8A.

FIG. 9 is an elevational view of an alternate embodiment of the clamping cartridge according to the Applicant's Prior Art Cartridge, shown in its closed/clamping position.

FIG. 10 is an elevational view of the alternate embodiment of the clamping cartridge of FIG. 9 but shown in its open/released position.

FIG. 11A is a perspective view of the clamping cartridge with the alternate operating mechanism in its closed/clamping position according to the preferred embodiment of the invention.

FIGS. 11B, 11C and 11D illustrate an elevational view, a plan view and an end elevational view of the clamping cartridge of FIG. 11A in its closed position.

FIG. 12A is a perspective view of the support frame or chassis of the clamping cartridge of FIG. 11A.

FIG. 12B is an elevational view of the support frame.

FIG. 12C is a plan view of the support frame.

FIG. 12D is a left end view of the support frame.

FIG. 12E is a right end view of the support frame.

FIG. 13A is a perspective view of the cam housing of the clamping cartridge of FIG. 11A.

FIG. 13B is an elevational view of the cam housing of FIG. 13A.

FIG. 13C is a plan view of the cam housing of FIG. 13A.

FIG. 13D is an end view of the cam housing of FIG. 13A.

FIG. 14A is a perspective view of the cam shaft of the clamping cartridge of FIG. 11A.

FIG. 14B is an elevational view of the cam shaft of FIG. 14A.

FIG. 14C is an end view of the cam shaft of FIG. 14A.

FIG. 15A is a perspective view of one cam of the clamping cartridge of FIG. 11A.

FIG. 15B is an elevational view of the cam of FIG. 15A.

FIG. 15C is an side view of the cam of FIG. 15A.

FIG. 16A is a perspective view of the movable channel of the clamping cartridge of FIG. 11A.

FIG. 16B is an elevational view of the movable channel of FIG. 16A.

FIG. 16C is an end view of the movable channel of FIG. 16A.

FIG. 17A is a perspective view of one of the slats for the movable channel of the clamping cartridge of FIG. 11A.

FIG. 17B is an elevational view of the slat of FIG. 17A.

FIG. 17C is an end view of the slat of FIG. 17A.

FIG. 18A is a perspective view of one of the clamping mechanisms of the clamping cartridge of FIG. 11A.

FIG. 18B is an elevational view of the clamp of FIG. 18A.

FIG. 18C is an end view of the clamp of FIG. 18A.

FIG. 19A is a perspective view of a retainer for the clamp of the clamping cartridge of FIG. 11A.

FIG. 19B is a plan view of the retainer of FIG. 19A.

FIG. 19C is an elevational view of the retainer of FIG. 19A.

FIG. 19D is an end view of the retainer of FIG. 19A.

FIG. 20A is a perspective view of the handle or crank for the cam shaft of the clamping cartridge of FIG. 11A.

FIG. 20B is an elevational view of the handle of FIG. 20A.

FIG. 20C is an end view of the handle of FIG. 20A.

FIGS. 21A-21D illustrate the clamping cartridge with the alternate operating mechanism as shown in FIG. 11A-11D in its closed position.

FIG. 22A is a perspective view of the clamping cartridge with the alternate operating mechanism being initially activated to commence opening of the clamping mechanisms.

FIGS. 22B, 22C and 22D illustrate an elevational view, a plan view and an end elevational view of the clamping cartridge of FIG. 22A in the beginning stages of opening.

FIG. 23A is a perspective view of the clamping cartridge with the alternate operating mechanism continuing to be actuated during opening of the clamping mechanisms.

FIGS. 23B, 23C and 23D illustrate an elevational view, a plan view and an end elevational view of the clamping cartridge of FIG. 23A in an intermediate stage of opening.

FIG. 24A is a perspective view of the clamping cartridge with the alternate operating mechanism actuated to a fully-opened position.

FIGS. 24B, 24C and 24D illustrate an elevational view, a plan view and an end elevational view of the clamping cartridge of FIG. 24A in an intermediate stage of opening.

FIG. 25 is a perspective view of a transportation/storage rack illustrating the use of the clamping cartridge of FIG. 1A.

FIG. 26 is an alternate perspective view of the rack generally opposite to that shown in FIG. 25.

FIG. 27 is a close-up of one of the rack's side clamping cartridges;

FIG. 28 is a close-up of one of the rack's bottom clamping cartridges.

FIG. 29 is a close-up, perspective end view of the lower portion of the rack.

FIG. 30 is a perspective view of a portion of clamping cartridge according to the present invention.

FIG. 31 is a side view of the clamping cartridge of FIG. 30 with the clamps closed.

FIG. 32 is a side view of the clamping cartridge of FIG. 30 with the clips open.

FIG. 33 is a partial section view of a boot of FIG. 30 on a clip.

FIG. 34 is a perspective view of a clip of FIG. 30 with its boots removed.

FIG. 35 is a front view of the clip of FIG. 34.

FIG. 36 is a side view of the clip of FIG. 35.

FIG. 37 is a perspective view of a cam wheel of FIG. 31.

FIG. 38 is a cross-section view of the cam wheel of FIG. 37.

FIG. 39 is a side view of the cam wheel of FIG. 37.

FIG. 40 is a perspective view of a retainer according to the invention.

FIG. 41 is a side view of a clamping cartridge according to the invention showing only a cam wheel, two retainers and a clip (in phantom outline).

FIG. 42 is a back view of a retainer with a clip installed.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1A-1D, there is shown an exemplary arrangement of the Applicant's Prior Art Cartridge. The clamping cartridge 10 comprises a plurality of spaced apart clamping mechanisms 12 arranged on a chassis or frame 14. The clamping mechanisms 12 (hereinafter referred to as clamps 12) have a pair of clamping arms 16 which cooperate with a spring clip 18 which urges the upper ends 20 of arms 16 toward one another in a jaw-like fashion. The lower ends 22 of the clamping arms 16 project through the frame 14 and act as levers which when moved relatively toward one another overcomes the spring force of the spring clip 18 thereby causing the clamp 12 to open (as seen in FIG. 2B). The resiliency of the spring clip 18 biases the clamp 12 toward a closed position.

The clamping cartridge 10 also includes means to actuate (open/close) the clamps 12 which preferably comprises a series of rotatable cam wheels 24, each of which having a cam surface 26 in contact with the lower end 22 of a clamp arm 16. The cam wheels 24 are disposed on a rotatable cam shaft 28. Advantageously, the cam wheels 24 can be provided with a cam surface 26 on each side, allowing the cam wheels 24 to be interdigitated between adjacent arms 22 a of adjacent clamps 12. Accordingly, for any number N of clamps 12, only N+1 cam wheels 24 are required.

The cam shaft 28 includes an extension 30 which can be used to rotate the cam shaft 28 and thus cam wheels 24. The extension 30 may be provided with means to facilitate rotation of the cam shaft 28, such as a knob or handle, or may include a lug which can be engaged by a wrench or similar tool. In the embodiment shown in FIGS. 1A and 2A, a handle 31 is insertable into a transverse aperture 29 (see FIGS. 1B and 2B) to effect leveraged rotation of shaft 28.

The cam surface 26 of the cam wheels 24 is axially and rotationally inclined such that by rotating the cam wheels 24, the point of contact with the lower end 22 of clamp arm 16 effectively translates axially. The cam surface 26 can be that which effectively results from an oblique cutting of a circular cylinder (i.e. a generally elliptical surface) as is the case in the preferred embodiment or could be a helical surface spiraling oppositely from both ends of the cam wheel (not shown).

As shown in particular in FIGS. 6A-6D, the cam surfaces 26 are such as to provide the cam wheels 24 with a thinner section on one side 32 and a thicker section on the opposite side 34. As seen in FIG. 1B, the thinner sections 32 of the cam wheels 24 are disposed between the adjacent lower ends 22 a of clamping arms 16 permitting maximum opening between the lower ends 22 of each clamp 12 and thus minimizing the distance between or closing (depending on the spatial relationships) the upper ends 20 of each clamp 12. The outermost cam wheels 24 a are disposed adjacent the lower end 22 b of the outermost clamp arm 16 a on outermost clamps 12 a. While it is not necessary that the outermost surface 26 a of outermost cam wheels 24 a be a cam surface, manufacturing efficiencies are achieved in producing a single or minimum number of cam wheel configurations.

Referring to FIGS. 2A-2D, when the cam shaft 28 is rotated such as by handle 31, the cam wheels 24 rotate so as to cause an increasingly thicker section thereof to wedge between adjacent lower ends 22 of adjacent clamps 12, thereby actuating the clamping arms 16 and thus opening the clamps 12′ in unison. Preferably, the amount of rotation of cam shaft 28 to effect full opening and closing of the clamps 12 is 180 degrees (or less). If the cam surface 26 b,26 c on both halves with of the cam wheel 24 is generally the same (i.e. the cam surface 26 is symmetrical about a vertical plane P as shown in FIG. 6D) then such a design will permit rotation of the cam wheel 24 in both directions (clockwise and counterclockwise) with the same effect.

A transverse chamfer 36 may be provided at the thickest section 34 in which the respective lower ends 22 of clamping arms 16 will center and seat when the clamps 12′ reach their fully open position. This allows the clamps to “lock” at or near their fully open position to permit items to be inserted into the clamps 12′ or removed therefrom. The chamfer also permits closer spacing of the clamps 12, 12′ and serves to reduce pressure on the cam wheels 24.

Details of the components of the clamping cartridge 10 are shown in FIGS. 3A to 7D.

FIGS. 3A-3D show the spring clip 18 the purpose of which in general is to provide biasing which urges the clamp 12 toward a closed or clamping position. The spring clip 18 has a generally U-shaped cross-section as shown in FIG. 3D having a pair of spring arms 40 separated by a bight 42. It will be appreciated that the spring clip 18 can be made in a variety of cross-sectional shapes, thicknesses and widths.

The spring clips 18 are fastened to the frame 14 by any conventional means. In embodiment shown, and pair of holes 44 are provided in the bight 42 while corresponding holes 44 are provided in frame 14 (see FIG. 5A) through which appropriate fasteners 48 (see FIGS. 1B, 2B and 2C) are used to secure the spring clip 18 to the frame 14.

The spring clips 18 are provided with a pair of slots 50 which correspond generally with pairs of slots 52 in frame 14 (see FIG. 5A). The slots 50 accommodate and help retain spring arms 16 while the slots 52 permit the spring arms 16 to extend through the frame 14 (as shown best in FIG. 1B). Preferably, the tips 54 of the spring arms 40 are sufficiently close such that when both clamping arms 16 are disposed within slots 50, the upper ends 20 of the clamping arms 16 are biased together. In FIG. 1B, the upper ends 20 of the clamping arms 16 are shown slightly separated. This is due to the fact that the insertion of the thinner sections 32 of the cam wheels 24 causes a slight pressure on the lower ends 22 of the clamping arms 16, thus causing the slight separation. Preferably, the spring clips 18 are made from known elastic materials such as spring steel.

FIGS. 4A-4C show one of the spring arms 16 of the clamp 12. The upper ends 20 may be relatively wider than the lower ends 22 to provide extended clamping/gripping support along a portion of the product edge. In this regard, the upper ends 20 may be covered or coated with a protective, high-friction material to reduce possible damage to the product to be clamped and to increase the clamp's gripping capability. For example, the upper ends 20 may be dipped in a liquid settable rubber compound or other attached protective cover. The lower ends 22 are designed to interface with the cam surface and thus may be provided with a rounded edge 56 to enable slippage to a certain extent. Preferably, the spring arms 16 are made from relatively stiff materials, such as stamped steel, so as to reduce the amount of bending over the force range expected to be encountered.

The frame 14 is shown in detail in FIGS. 5A-5C. The frame 14 provides the basic supporting structure for the clamps 12 and cam shaft 28 (as shown in FIG. 1B). Thus the frame 14 may be conveniently made by bending an appropriate sheet material into a three sided, rectilinear configuration having an elongated central section 60 and two end sections 62. As aforesaid, the central section 60 includes holes 44 by which the clamps 12 are affixed thereto by fasteners 48 and slots 50 through which the clamping arms 16 of the clamps 12 extend. The end sections 62 each include an aperture 64 in which the cam shaft 28 can be journaled or in which a bearing for the cam shaft 28 can be provided. The frame 14 may also include mounting flanges 66 which include holes 67 for mounting the cartridge 10 where desired. While the preferred frame 14 has been shown with open sides 68 which reduces material costs and facilitates manufacturing thereof, the sides 68 can be closed where it is desired to restrict access to the cam wheels 24 or to inhibit ingress of dust and other foreign matter into the working components of the cartridge 10.

The cam wheel 24 is shown in detail in FIGS. 6A-6D. When viewed along its axis (FIG. 6D), the cam wheel 24 has an outer circular configuration. The cam wheel 24 includes a central bushing 70 and an aperture 72 by which the cam wheel 24 can be mounted on the cam shaft 28. The aperture 72 includes a keyway 74 for accommodating a key 76 (see FIG. 1B) associated with the cam shaft 28 to prevent the cam wheels 24 from rotating relative to the cam shaft 28. The cam angle θ is generally a function of the diameter of the cam wheel 24 and the desired longitudinal movement of the lower ends 22 of the clamping arm 16 (to effect a correspondingly opposite proportional movement of its upper end 20 and hence an opening of the clamp 12).

Preferably, the cam wheels 24 are individual and identical for greater manufacturing efficiency and flexibility. Depending on the length of bushing 70, a cam wheel 24 may abut the bushing 70 of an adjacent cam wheel 24 (as shown in FIG. 1B) or may be relatively free to move along the keyed cam shaft 28, there being a certain degree of self-centering/alignment on account of the clamping arms in the latter case. Still, if spacing between cam wheels becomes significant, (required by panel separation and/or clamp size), washers may be introduced, as a precaution or as a visual enhancement, although they may not be required for the operability of the device. Alternatively, the cam wheels may be made integrally with one another. The cam wheels 24 may be made from any suitable material such as metal (steel, aluminum, etc.), hard plastics, Teflon™, etc. and they can be machined, stamped, injection molded, or any other suitable method of manufacture. The material should provide mechanical robustness, and a reasonable life-time under friction. The materials for the cam wheels 24 and the contacting portion of the clamping arms 22 can be chosen to have a sufficiently high coefficient of friction such that the cam wheels 24 will remain in whatever position they are in when rotation of the shaft is stopped (which may or may not be at top or bottom dead center). Alternatively, the chosen materials can have a sufficiently low coefficient of friction whereby the pressure exerted by the clamping arms 22 on the camming surfaces 26 causes the cam wheels 24 to rotate toward the clamp closed position, thereby resulting in a clamping cartridge which is normally biased in the closed position.

Lastly, the cam shaft 28 is detailed in FIGS. 7A-7C. The shaft 28 has two annular grooves 80 spaced apart slightly greater than the distance between end sections 62 of frame 14 for accommodating retaining rings 82 (as shown in FIG. 1B). The shaft 28 has a keyway 84 which cooperates with key 76 (as shown in FIGS. 1B and 1D) to enable rotation to be imparted from the shaft 28 to the cam wheels 24. Alternatively, a splined shaft could be provided with the apertures in the cam wheels being correspondingly splined. The shaft 28 may be made from any suitable material typically used for shafts.

FIGS. 7D and 7E illustrate an alternate mechanism for assisting in the imparting of rotational movement in the form of a lug 29′ which is provided on the extension 30′ of alternate shaft 28′. A wrench (not shown) is engageable with the lug 29′ for rotating the shaft 28′. Any other known mechanism could likewise be employed for manual rotation of the shaft or a power-driven device could easily be substituted.

Referring to FIGS. 1B, 2B and 8A-8D, to operate the clamping cartridge 10, the cam shaft 28 is rotated by the handle means 31, which causes the cam wheels 24 which are keyed to the cam shaft 28 by key 76 to rotate. As the section of the cam wheel 24 disposed between adjacent clamps increases in thickness, relatively speaking, or alternatively, as the distance between the upper ends of adjacent cam wheels 24 decreases, the clamps 12 are urged toward an open position 12′ but remain biased against the force of the spring clips 18. As the cam shaft 28 rotates to 180 degrees, the lower ends 22 of the clamping arms 16 self-center against the chamfered edge 36 of the cam wheel 24, thereby retaining the clamping cartridge 10 in its open position. In the cartridge's open position as shown in FIG. 2B, the individual clamps 12′ are open to receive a portion of the edge(s) 90 of the panel-like object(s) 92 (shown schematically). One or more panels 92 (having a total thickness less than the design width of the open clamp 12′) are positioned in one or more of the open clamps 12′ and the cam shaft 28 is again rotated (either through to 360 degrees or back to 0 degrees) to close the clamps 12 against the inserted panel(s) 92. Since each of the clamps 12 are individually biased toward a closed position, the clamps 12 will naturally adjust to the thickness of the retained panel(s) 92 as shown best in FIG. 8B. Accordingly, the clamping cartridge 10 can accommodate a series of different panels comprising panels of different thicknesses 92 a,92 b and/or a varying number of panels 92 c,92 d of same or different thickness within each clamp 12, as shown in FIGS. 8A-8D. This will permit variability in loading or unloading (i.e. random access) and typo-dimensional sequencing for products retained within the clamping cartridge 10. When release or removal of one or more panels 92 is desired, the cam shaft 28 is rotated 180 degrees in the same manner as aforesaid to open the clamps 12 in unison. When the desired panels have been removed, the cam shaft 28 can be actuated again to close clamps 12 against the remaining panels.

The individual biasing of the clamps 12 can be achieved in a number of ways. The embodiments shown herein employ a clip-type spring although this is not to be considered limiting. The positioning of the spring clip 18 in the aforementioned embodiments is shown to be above the frame 14. However, depending on the nature of the spring or biasing mechanism being used, positioning can be varied just so long as the function remains.

Instead of having the jaws of the clamp used to clamp the article and the clamping arms (levers) bearing on the camming surface of the cam wheels, the clamps can be reversed such that the jaws engage the opposed camming surfaces of the cam wheel and the articles are then clamped between adjacent clamping arms of adjacent clamps as shown in the alternate embodiment illustrated in FIGS. 9 and 10. The alternate clamping cartridge 120 shares many of the same components as the clamping cartridge 10 of FIG. 1A, such as the cam shaft 28 and associated cam wheels 24. The frame 122 is similar but its dimensions may require alteration to accommodate the clamps 124 in their reverse orientation. The clamps 124 are disposed such that their spring clips 126 are beneath the frame 122 and with their arms 128 extending thereabove through the slots 130 in the frame 122. The thin section 32 of the cam wheels 24 are positioned between the jaws 132 of the clamps 124 such that the tips 134 of the clamping arms 128 engage the opposed camming surfaces 26 of the cam wheels 24. As the shaft 28 is rotated, the portion of the cam wheels 24 between the jaws 132 becomes increasingly thicker, relatively speaking, causing the distal ends 136 of the arms 128 of each clamp 124 to move relatively toward one another and hence away from the distal end 136 of the adjacent arm 128 of the adjacent clamp 124. Continuing the rotation to 180 degrees as shown in FIG. 10, the jaws 132 over-center onto the chamfers 36 to “lock” into an opened position. Panels 140 which may have been disposed between adjacent arms 128 of adjacent clamps 124 are then removable. Alternately, panels 140 may be situated between adjacent arms 128 of adjacent clamps 124 whereupon rotation of the shaft 28 (either through to 360 degrees or back to 0 degrees) returns the thinner section 32 of the cam wheels 24 to between the jaws 132, relaxing/reducing the tension on the spring clips 126, and reducing the distance between the distal ends 136 of the adjacent arms 128 of the adjacent clamps 124, which effectively permits them to act as clamps.

The outermost clamps 124 a, 124 b as shown in FIG. 9, may include only one clamping arm 128 a, 128 b, respectively, as an outermost clamping arm 128 c, shown in phantom, would be unnecessary in this arrangement. However, an outermost arm 128 c could be provided. It can be seen that the alternate clamping arrangement 120 requires the same number of clamps 124 as cam wheels 24. However, the number of cam wheels 24 is still one greater than the number of clampable articles 140 as the clamping function is based on the spacings between adjacent clamps 124.

Referring to FIGS. 11A-11D, there is shown the clamping cartridge 211 having the alternate operating mechanism which represents the best mode according to the invention.

The components of the clamping cartridge 211 are referenced with numerals 201 through 210, details of which are shown in FIGS. 12A-12D to 20A-20D. The clamping cartridge 211 is similar to the clamping cartridge 10 shown in FIGS. 1A-8D, especially in operation, the difference being mainly related to the manner by which the individual clamping mechanisms are actuated between opened and closed positions and vice versa.

Clamping cartridge 211 comprises a plurality of spaced apart clamping mechanisms 208 (see FIGS. 18A-18C) arranged on a chassis or frame 201, similar to frame 14 of FIGS. 1-8. The clamping mechanisms 208 (hereinafter referred to as clamps 208) have a pair of clamping arms or jaws 216 which are normally inwardly biased (for example, if made of spring steel or the like) so that the tips 235 thereof converge together so as to close the clamp 208 in the absence of external forces. The individual clamps 208 are affixed to the frame 201 by means of respective retainers 209 (see FIGS. 19A-19D) and suitable fasteners, not shown, which secure the bight 242 of the clamp 208 to the frame 201.

For opening the jaws 216 of the clamps 208, a movable slotted guide 213 is provided through which the jaws 216 of the clamps 208 extend. Preferably, the guide 213 is constructed of a channel 206 (see FIGS. 16A-16C) having a plurality of spaced-apart slats 207 (see FIGS. 17A-17C) affixed transversely thereto by suitable fasteners, not shown, through holes 231 in the slotted guide 213 (see FIG. 16B) and holes 227 in slats 207 (see FIG. 17B), for example. The spaced-apart slats 207 provide therebetween a number of transverse slots 215 through each of which a pair of jaws 216, that is adjacent ones from adjacent clamps 208, extend therethrough, with the exception of the outermost clamps wherein only the single outermost jaw extends therethrough. It will be appreciated that individual slots could be provided for each jaw but the sharing of slots 215 between adjacent jaws will make the guide less complex. The slotted guide 213 is movable relative to the frame 201. By moving the slotted guide 213 in the direction of the opening of the clamp, the jaws 216 are constrained within the slots 215 and are thereby forced to pivot towards perpendicular from their normally inwardly angled position as the distance between the frame 201 and guide 213 increases and back as the distance between the frame 201 and guide 213 decreases. The channel 206 has sufficient depth D (see FIG. 16C) to accommodate the length of travel required to fully open the clamps 208, which is generally at least the length of the jaws 216. Use of individual retainers 209 and slats 207 facilitate assembly.

A camming mechanism is employed to control the movement of the slotted guide 213 relative to the frame 201. One or more (two as shown in the drawings) cam housings 202 (see FIGS. 13A-13D) are affixed to the slotted guide 213, particularly on the underside of channel 206, using suitable fasteners, not shown, through holes 225 in the slotted guide 213 (see FIG. 16B) and holes 227 in housings 202 (see FIG. 13A), for example. Braces 203 are be welded to the cam housings 202 for strengthening purposes and or to assist with guiding the movement of the slotted guide 213 and cam housings 202 as shown in FIG. 13A. Each cam housing 202 encloses a cam wheel (or simply “a cam”) 205 (see FIGS. 15A-15C) which is mounted on a mutual cam shaft 204 (see FIGS. 14A-14C) which extends though slots 217 in the cam housing 202 and is rotatably mounted to frame 201 through apertures 219 (see FIG. 12A). Cam surface 223 contacts both inner sides of housing 202.

The cam shaft 204 includes an extension 230 which can be used to rotate the cam shaft 204 and thus cam wheels 205. The extension 230 may be provided with means to facilitate rotation of the cam shaft 204, such as a handle 210 (see FIGS. 20A-20C), or may include a lug which can be engaged by a wrench or similar tool. In the embodiment shown in FIG. 1A, the handle 210 is screwable into a transverse threaded aperture 229 (see FIG. 11C) to effect leveraged rotation of shaft 204.

For ease of manufacture, the cams 205 are circular, but are mounted via off-centre aperture 221 with respect to the cam shaft 204. By rotating the cam shaft 204, the cams 205 rotate and urge their cam surface 223 against the cam housing 202, causing the housing 202 to move relative to the frame 201, hence the reason for slots 217 in the housings 202. Depending on friction between the contacting components, the rotational position may be self-maintaining, but preferably, low friction components are utilized so that the biasing force of the clamps 208 against the slots 215 is sufficient to always urge the clamping cartridge into its closed position.

Thus, as with the embodiments illustrated in FIGS. 1A-8D and FIGS. 14-15, the clamping cartridge 211 also employs a camming mechanism to effect unitary operation of the individual clamps.

Referring to FIGS. 21A-21D to 24A-24D, to operate the clamping cartridge 211, the cam shaft 204 is rotated by the handle means 210, which causes the cam wheels 205 which are affixed to the cam shaft 204 to rotate. The rotation of the cams 205 causes the cam housings 202 and hence the slotted guide 213 to move relative to the frame 201. Initially, as shown in FIGS. 22A-22D, nominal movement occurs. However, continued rotation of the handle/cam shaft/cams 210, 204, 205 as shown in FIGS. 23A-23D results in greater relative movement of the slotted guide 213, with the confinement of the slots 215 causing the straightening (towards perpendicular) of the jaws 216 of clamps 208 by overcoming the closing bias of the jaws 216. At the fully rotated position shown in FIGS. 24A-24C, the jaws 216 of clamps 208 are fully opened to receive therebetween (or release) a portion of the edge(s) of the panel-like object(s) 92 (shown schematically). The handle 210 may then be reversely rotated (or forwardly rotated through 3600) to cause the slotted guide 213 to lower, thereby relaxing the bias-overcoming force and eventually retaining the panel-like object 92 between the jaws 216 of the clamp 208.

Since each of the clamps 208 are individually biased toward a closed position, the clamps 208 will naturally self-adjust to the thickness of the retained panel(s) 92. Accordingly, the clamping cartridge 211 can accommodate a series of different panels comprising panels of different thicknesses and/or a varying number of panels of same or different thickness within each clamp 208. This will permit variability in loading or unloading (i.e. random access) and typo-dimensional sequencing for products retained within the clamping cartridge 211. When release or removal of one or more panels 92 is desired, the cam shaft 204 is rotated in the same manner as aforesaid to open the clamps 208 in unison. When the desired panels have been removed, the cam shaft 204 can be actuated again to close clamps 208 against the remaining panels 92, if any.

The clamping cartridges 10, 120, 211 can be used in a variety of storage and/or packaging systems. The cartridges can be used in a variety of containers like hard (plastic) bins, totes, wooden and even paper (cardboard) structures, as well as on carts, cars, dollies, elevators, conveyors, or in fixed applications (on walls, on floors, on structures of any kind). In one such application shown in FIGS. 25-29, a glass-panel storage rack 300 is realized comprising a frame 302 to which a generally horizontal bottom support 303 a and a generally vertical side support 303 b are attached. At least one clamping cartridge 10 (as shown, or clamping cartridge 120 or 211) is preferably provided in association with each support 303 a, 303 b such that the clamping mechanisms 12 a of the horizontal support cartridge(s) 10 a align in the same plane with the corresponding clamping mechanisms 12 b of the vertical support cartridge(s) 10 b. The clamping cartridges 10 a, 10 b can then be opened as aforesaid so as to enable the edges 304 a, 304 b of glass panels 305 to be positioned within the clamps 12 a, 12 b, respectively. The clamping cartridges 10 a, 10 b can then be closed as aforesaid so as to clampingly retain the glass panels 305 within the rack 300.

When any one of the glass panels 305 is to be removed, the clamping cartridges 10 a, 10 b are opened and the panels 305 can be removed as desired. Although when the clamping cartridges 10 a, 10 b are opened, all of the clamping mechanisms release, the edges 304 a, 304 b of glass panels 305 are still bounded by the clamping arms 16 (jaws) and thus the panels 305 should remain in place until removed. However, it may be desirable to incline the rack 300 to take advantage of gravity to ensure the panels 305 stay in the rack 300 when the clamping cartridges 10 a, 10 b are opened. In the embodiment shown in FIGS. 25-29, the frame 302 is maintained generally upright while the bottom and side supports 303 a, 303 b are tilted as shown by angle alpha. in FIGS. 25, 26 and 29.

The rack 300 may also include separate seating/supporting devices 306 (shown best in FIGS. 27, 28 and 29) for the panel whereby the weight of the panels is supported thereby. The clamping cartridges 10 a, 10 b are positioned such that the jaws 20 are engageable with the edge portion 304 a, 304 b of the panels 304 without the panels' weight resting on or abutting against the bight 42 of the clamps 12 as shown, for example, in FIG. 27. In this regard, the rack 300 separates the gripping/clamping task/function from the gravitational, supporting functions. The use of separate seating/supporting devices 306 reduces the need for more robust clamps and provides more economical cushioning and surface distribution capability versus having it built into the clamps. As shown, the seat/supports 306 have a multiple-U-shaped cross-section seen best in FIG. 29, which is attachable to convenient locations on the bottom and side supports 303 a, 303 b, wherein the parallel channels 308 are aligned generally with the clamps 12 of the clamping cartridges 10. In the case of the lower seat/supports 306 a on the bottom support 303 a, the edge bearing surfaces 310 extend above the bights 42 of the clamps 12 of the cartridges 10 a but not above the upper ends of the arms 20, whereas the edge bearing surfaces 310 of the side seat/supports 306 b on the side support 303 b, extend inwardly of the bights 42 of the clamps 12 of the cartridges 10 b but not beyond the upper ends of the arms 20.

Depending on the arrangement of clamping cartridges 10 and seat/supports 306 in a given rack 300, it may be possible to use the rack 300 to store or transport not only a plurality of identical articles, but also differing articles. As can be seen in FIGS. 25 and 26, different sets of glass panels 305 a, 305 b, 305 c are retained in the rack 300 although only three of the four clamping cartridges 10 are used, only two of which are common to all sets of glass panels 305 a, 305 b, 305 c. FIG. 28 shows how the seat/supports 306 cradle the remote (from the clamps) edges 304 c of the glass panel 305 c. Depending on the clamping strength and the article to be clamped, it may only be necessary to employ one clamp 12 per article (hence a single clamping cartridge 10) and, where necessary, utilize one or more aligned seat/supports 306 to support and prevent movement of non-clamped edges.

The seat/supports 306 can be made of any appropriate material bearing in mind the articles expected to be transported or stored in the rack 300. As shown, the seat/supports 306 are made from an extruded plastics material.

Advantageously, the bottom and side supports 303 a, 303 b can comprise a plurality of slats 312 on which the clamping cartridges and seat/supports 306 are mounted. By having the slats 312 moveable/adjustable with respect to the frame 302 and hence the spacing between adjacent clamps, the rack 300 can readily be adapted to accommodate a wide variety of articles.

Depending on the number of clamping cartridges employed in any one rack and their accessibility, it may be advantageous to provide a linkage mechanism (not shown) to operate them simultaneously or to utilize power-driven shafts with an associated control unit (not shown) to selectively rotate the shafts individually or simultaneously.

Since the clamping cartridges 10, 120, 211 function in the same manner, their use in a rack 300 would be the same as explained above with clamping cartridge 10.

The Applicant has made certain improvements to the Applicant's Prior Art Cartridge which are described below and which comprise the present invention.

Referring to FIGS. 30 to 42, an improved centre cam clamping cartridge indicated generally at 400 according to the invention can be used in the Applicant's Prior Art Cartridge in place of the clamping cartridge 10. The clamping cartridge 400 comprises a plurality of clamps indicated generally at 402 arranged on a frame 404. Only a portion of the clamping cartridge 400 is shown. It will be understood by those skilled in the art that the number of clamps 402 can be varied according to specific applications.

The clamps 402 are formed of a single piece of material and have a base 406 and two arms 408. The base 406 includes a concave central section 408 and arcuate end sections 410 which extend into arms 408. The arms 408 in the normal closed position are spring biased towards each other and contact each other at the upper ends 411 of the arms in a jaw-like fashion due to the resiliency of the arms 408. Preferably, the clamp 402 is made from relatively stiff materials, such as stamped steel.

The clamping cartridge 400 also includes means to open and close the clamps 402 which comprises a series of rotatable cam wheels 412 inside the clamps 402. The cam wheels 412 are disposed on a rotatable cam shaft 416. One cam wheel 412 is provided for each clamp 402.

Each cam wheel 412 has an outer circular configuration and includes a hexagonal aperture 414 for receiving the cam shaft 416. The cam wheels 412 have a wedge-shaped side profile as shown in FIG. 38 with a thinner section 418 which is narrow enough to permit the clamps 402 to close completely when the first end is adjacent the upper ends 411 as shown in FIG. 31 The cam wheels 412 have a thicker section 420 which is wider than the first end 418 and sufficiently wide to force the arms 408 apart when the second end 420 is adjacent the upper ends 411 as shown in FIG. 32.

The cam shaft 416 is hexagonal in cross-section and includes an extension 422. The extension may be provided with means (not shown) to rotate the cam shaft 422, such as a knob or handle.

The cam shaft 416 can also be used in place of the round shaft 28 described above with respect to the Applicant's prior Art Cartridge with appropriate modifications. Similarly, the round shaft 28 can be used in place of the hexagonal shaft 422 with appropriate modifications that will be evident to those skilled in the art.

Referring to FIGS. 31 and 32, when the cam shaft 416 is rotated (such as by a handle), the cam wheels 412 rotate so as to cause an increasingly thicker section thereof to wedge between the inner walls 424 of the clamp 402 in which the cam wheel 412 is positioned, thereby actuating the arms 408 and thus opening the clamps 402 in unison. Preferably, the amount of rotation of cam shaft 416 to effect full opening and closing of the clamps 402 is 180 degrees (or less). If the cams 412 are generally symmetrical about their longitudinal axis then such a design will permit rotation of the cam wheel 412 in both directions (clockwise and counterclockwise) with the same effect.

A transverse chamfer similar to the chamfer 34 in the Applicant's Prior Art Cartridge may be provided at the thickest section 420 to allow the clamps 412 to “hold” at or near their fully open position to permit items to be inserted into the clamps 402 or removed therefrom.

FIGS. 34 to 36 show one of the clamps 402. The clamp 402 has a hole 426 in each arm 408 for receiving the shaft 416. The upper ends 416 each include outer teeth 428 formed by a slot 430 and a pair of inner teeth 432 formed by a cut out well 434 in the centre of the upper end 416.

The teeth 428 and 432 are used to retain a fitted boot 436 on the upper ends 411. The boot 436 reduces possible damage to a product being clamped and increases the gripping capability of the clamps 402.

Referring to FIG. 33, the boot 436 is made of two plastic walls (one of which is shown as 438). The walls 438 are joined at the ends and in the middle by bridges 440 and 442 formed by heat sealing the walls 438 together. The bridges 440 and 442 are engaged by the teeth 432 and 428 respectively.

The frame 404 is shown in FIG. 30. The frame 404 provides the basic supporting structure for the clamps 402 and cam shaft 416. Thus the frame 404 may be conveniently made by bending an appropriate sheet material into a three sided, rectilinear configuration having an elongated central section 444 and two end sections 446. A mounting flange 448 includes a bushing 450 with an aperture 452 for receiving the cam shaft 416. An identical mounting flange, (not shown) is located at the opposite end of the frame 404.

Referring to FIGS. 40 to 42, the clamps 402 are affixed to the frame 404 by two elongated retainers indicated generally at 454 made of suitably rigid material such as molded plastic. One of the retainers 454 is shown in FIG. 40. The retainer 454 includes a rectangular base section 458 and a plurality of teeth indicated generally at 456 (one for each clamp 402) extend from one side of the retainer 454. Each retainer 454 is affixed to the frame 404 by rivets 462 inserted into holes 461.

The teeth 456 include a back wall 466 and two side walls 468. The side walls 468 are triangular in side profile and have an inner vertical surface 470, an outer inclined surface (also referenced by 468) and a top inclined surfaces 472.

The bottom of the teeth 456 is formed by a flange 459 which extends from one side of the retainer 454. The bottom surface 474 of the flange 459 is concave.

The concave central section 408 of each clamp 402 nest in the concave bottom surfaces 474 of the two teeth 456 which retain the clamps 402 on the frame 404 by overlapping sections of the section 408 from both sides of the clamp 402.

Referring to FIG. 41 the teeth 456 are positioned adjacent the cams 412 such that the cam wheels 412 are permitted to rotate free of the teeth 456.

Pieces sometimes break off of the materials inserted into the clamps 12 of the Applicant's Prior Art Cartridge and fall onto the cam wheels 24. Such debris can interfere with the operation of the cam wheels 24.

In the present invention, the teeth 456 and in particular the inclined surfaces 472 act as slides to deflect debris falling onto the cam wheels 412 away from the cam wheels 412. Debris falling into a cam wheel 412 slides down the ramps 472 and away from the cam wheels 412.

While the present invention has been described with reference to specific exemplary embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the invention as set forth in the claims. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. 

1. A clamping cartridge for releasably clamping a plurality of panel-type articles in generally parallel spaced-apart manner comprising: a frame; clamping means spaced-apart along the frame, said clamping means being generally oriented perpendicular to their direction of spacing and being normally biased towards a closed position; actuation means operable in association with said clamping means for opening and closing said clamping means in unison; and a slide associated with each of said clamping means.
 2. The clamping cartridge of claim 1, wherein said clamping means include one or more clamps; said actuation means includes cam means associated with said clamping means.
 3. The clamping cartridge of claim 2, wherein said actuation means further includes a shaft; said cam means includes a cam wheel having a hole therethrough for receiving said shaft to mount said cam wheel on said shaft, and said clamping means includes a clamp with two arms, each having a hole therethrough for receiving said shaft; wherein said cam wheel is situated between said arms or said clamp.
 4. The clamping cartridge of claim 3, wherein said shaft is hexagonal in cross section and said hole in said cam wheel is correspondingly hexagonal in profile and whereby rotation of said shaft imparts a corresponding rotation to said cam wheel to open or close said clamp.
 5. The clamping cartridge of claim 3, wherein said slide is adjacent said cam wheel.
 6. The clamping cartridge of claim 5, wherein said slide includes an inclined surface inclined downwardly away from said cam wheel.
 7. The clamping cartridge of claim 3, further including boot means on the ends of said arms of said clamp.
 8. A clamp for a clamping cartridge comprising: a base and two arms forming a jaw, wherein each of said arms include an end, wherein said ends of said arms are biased toward each other; and a boot on each of said ends.
 9. The clamp of claim 8, wherein each said end of said arms include a retaining means for retaining said boot on said arm.
 10. The clamp of claim 9, wherein said retaining means include teeth and said boot includes bridges which are engageable by said teeth to retain said boots on said arms.
 11. The clamp of claim 10, wherein said boot includes two walls and wherein said walls are joined together by said bridges.
 12. A clamp according to claim 10 wherein said teeth includes a pair of outer teeth formed by a slot cut out of the wall and a pair of inner teeth formed by a well.
 13. A retainer for a clamping cartridge comprising: a base; a tooth extending from one side of the retainer, said tooth including a top inclined surface, a back wall and two side walls, and a flange.
 14. The retainer of claim 13, wherein said clamping means includes a clamp including a base and two arms extending from said base, said tooth extends from said base between said arms of said clamp thereby securing said clamp.
 15. A clamping cartridge for releasably clamping a plurality of panel-type articles in generally parallel spaced-apart manner comprising: a plurality of spaced-apart clamps, said clamps being generally oriented perpendicular to their direction of spacing and each having a pair of relatively movable jaws; actuation means operable in association with said clamps for causing the jaws of all said clamps to move in unison relative to one another, said actuation means comprising a cam operable between the jaws of each clamp whereby movement of the cam causes the relative movement of said jaws, wherein said jaws are normally biased so as to be individually self-adjusting to the presence of an edge of one or more panel-type articles placed therebetween; and slide means associated with said clamps.
 16. The clamping cartridge of claim 15, wherein the cams are rotatable and have a cam surface engageable with a respective interior wall of said jaws of each clamp.
 17. The clamping cartridge of claim 16, wherein said cam is tapered transversely with respect to an axis of said cam and said jaws are angled relative to the cam such that there is a relative overlap transverse to the axial direction between a wider side of the cam and the angled jaws, wherein when the cam is rotated, the wider side traces a circular path of rotation which intersects with the angled jaws of the clamp to force the jaws to open and to permit them to close as the cam is rotated.
 18. The clamping cartridge of claim 17, wherein said cams are disposed on a rotatable cam shaft which is hexagonal in cross-section.
 19. The clamping cartridge of claim 18, wherein the cam shaft projects though an aperture in said jaws of said clamps.
 20. The clamping cartridge of claim 18, wherein an aperture is provided in said cam through which said cam shaft is insertable, said aperture having a shape generally corresponding to the cross-sectional shape of the cam shaft so as to prevent relative rotational movement therebetween and to allow said cams to be axially slidable along said cam shaft. 